There is known e.g. an analog pressure vessel for obtaining composite materials at high pressures and temperatures, containing a frame, closures with movable seals, a yoke with the upper and lower cross-bars absorbing the axial stress. The frame and the yoke are made immovable with respect to each other, and only the upper yoke cross-bar is made detachable (Inventor's Certificate of the USSR No. 412922, B01 J 3/04 of Feb. 09, 1971).
The shortcoming of this analog vessel is that it enables only the top loading of the material into the pressure vessel. Moreover, forged-welded or multilayer design of this high pressure vessel without built-in elements providing for cooling of the high pressure vessel itself, reduces significantly its technological capabilities both in terms of using high pressures and especially high temperatures during technological processing, as well as decreases its reliability and operational safety.
There is also known a second analog device for thermal treatment of powder materials under high pressure using high temperatures, as described in the USSR patent No. 402185, B 22 F 3/14 of Dec. 10, 1973. This analog excludes many shortcomings of the previously described analog since its block for absorbing the axial force during processing, is made in the form of a press column consisting of two (upper and lower) all-metal cylinders, a stay rod and a strip bandage. The pressing chamber itself contains a high-pressure cylinder consisting of a tube with end rings and pre-stressed band fixed on it. The working chamber contains an electric heating element and a cooling and high-pressure gas feed system. The press column is installed on rails.
The device for thermal treatment of powder materials under high pressure, adopted as the second analog, excels the first analog significantly by its technological capabilities because it allows to carry out technological processing at higher temperature and pressure ranges.
However, the design solution of the blocks that absorb pressure stresses has a series of essential shortcomings that reduce technological capabilities of the device during operation and lower the cost-effectiveness and the safety of the design in general. Thus, f. ex., the design solution of the high-pressure cylinder, though reinforced by the band, has a low-efficiency cooling system what restricts the temperature range of the technological process and increases the cooling liquid consumption.
On the other hand, the design of the press column containing all-metal cylinders is highly metal-consuming. Generally, such design involves high manufacturing costs what makes it uneconomical.
The nearest analog (prototype) of the declared technical solution, “Pressure Module of Autoclave”, is the prospectus of ASEA company AQ00-102R, of 1977, where a principal design of isostatic press is described in detail.
The prototype isostatic press (autoclave module) has a high-pressure vessel consisting of a high-strength steel cylinder with a winding made of pre-stressed steel wire, the end closures for axial sealing of the vessel, and a yoke. The frame consists of two all-metal half-cylindrical rams and two columns that separate them. The rams and the columns are reinforced by a large number of layers of pre-stressed high-strength wire.
This prototype isostatic press has significant advantages over the above described analogs, primarily by ensuring its high operational safety.
However, the prototype isostatic press is extremely high metal-consuming. All-metal (cast, forged etc.) design of rams leads by itself to high consumption of metal while complete overlapping of end closures by the rams makes the matter even worse. Other shortcomings of the same order include all-metal design of columns located between the rams. The frame of the prototype apparatus in general is highly metal-consuming and heavy, what complicates the operation and requires additional hoisting & transporting equipment and, therefore, increase in the height of the working shop and additional costs. Moreover, the design of the vessel itself made of one high-strength cylinder, though reinforced by wire winding, cannot fully guarantee an efficient cooling of the vessel's working chamber, what also leads to restrictions of the technological process's parameters.